Visits to the outer solar system are usually conducted as NASA flagship missions that cost billions of dollars, like the recently concluded Cassini mission to Saturn or the Europa Clipper spacecraft set for launch in the 2020s.

While these projects have produced significant achievements, smaller, less pricey missions also might advance planetary science. On Mars, for instance, no single spacecraft did everything, but in aggregate and over time, the robots sent there revealed the planet’s watery past and set the stage for future astronauts.

That’s why the scientists behind Trident proposal, which will be formally presented to NASA later this month, are seeking support under the agency’s highly competitive Discovery program, for missions that are supposed to cost less than $500 million.

NASA is changing one of the key scientific instruments on Europa Clipper, its next major mission to the outer planets of the solar system, and has brought in a scientific luminary to lead it, project leaders announced today. Clipper is set to orbit Jupiter and study Europa, the icy Jovian moon, across multiple flybys. Earlier this month, NASA headquarters terminated the mission’s ICEMAG magnetometer instrument, citing overruns in its estimated budget. The move left the spacecraft without an essential tool to study Europa’s interior ocean, where astrobiologists hope extraterrestrial organisms might be found.

Margaret Kivelson, a professor emerita at the University of California, Los Angeles, will lead the effort to develop a simplified magnetometer to replace ICEMAG. The instrument will measure Europa’s magnetic field and gather data on the ocean’s depth and salinity. Kivelson previously led the magnetometer team on the spacecraft Galileo, which orbited Jupiter in the 1990s. She is credited with discovering the ocean beneath Europa’s ice shell.

MER came in the aftermath of failed mission proposals by Ray Arvidson, a professor at Washington University in St. Louis; Larry Soderblom of the U.S. Geological Survey; and Steve Squyres, a professor at Cornell University. Each of the three had been beaten by David Paige of University of California, Los Angeles, whose ill-fated Mars Polar Lander was selected for flight by NASA.

“During an [American Geophysical Union] meeting, I stopped Steve in the hall,” says Arvidson. “I said, ‘I’m a pretty sore loser. How about you?’ And that was the start.” Arvidson, Squyres and Soderblom merged their various teams and set about writing a joint proposal to get a rover on the Martian surface.

Once it reaches the bottom of the pit, Kerber says, Axel would explore the cavern floor, providing humanity’s first close look at the subterranean realms of the moon. The rover would carry six times as much tether as it needs, so however far the bottom of the cavern is, Axel should be able to descend deeply enough to discover what waits below.

“The bottom of the pit is total exploration. We have enough time to just see what the heck is down there. We are thinking a monolith,” Kerber jokes, “or a big door covered in hieroglyphics.”

This is my second year covering the Lunar and Planetary Science Conference, an annual gathering in Houston, Texas of the world's planetary scientists. Most of my coverage will appear at mental_floss, and I'll post links as they go live. I suspect if you've arrived here, it's from one of my m_f pieces. If you enjoyed that work, here are a few pieces of note that I've written about planetary science and external issues affecting the field.
The Scientists Who Conquered Pluto, The Week

We know well the way astronauts think because we've studied them for so long — lionized them, rightfully, in books and movies and on television. We understand the human adventure. We understand that astronauts train hard and while in space live in pretty miserable conditions. But we also understand the glory of being an astronaut. They are humanity's ambassadors. They are exploring the final frontier. They've played golf on themoon! But what of these people — the New Horizons people, these spacecraft pilots and planetary scientists who study the outer reaches of the solar system? What can be made of them? Alice Bowman said the words, "We are outbound from Pluto." Has a more breathtaking string of words ever been uttered?

The lighting of Pluto is a coming of age for humankind. It is the end of one thing — proving that we can visit any world we so choose — and the beginning of something profound: looking outward, beyond the orbits of the planets, with an eye toward active exploration. Contrary to common lamentations, NASA is not an agency flush with cash (its total budget takes up less than one half of one percent of the federal budget), and it is not an agency adrift. We are, in fact, living in a golden age of space exploration. In a five-year span, humanity will have visited the farthest planet in the solar system and set a course for the Kuiper Belt (long hypothesized, but only discovered in 1992); executed a hair-raising entry, descent, and landing of the Mars Science Laboratory; and rewritten the books on Mercury and Saturn, based on the astonishing discoveries of MESSENGER and Cassini, respectively.

Two years ago, NASA’s Mars Atmosphere and Volatile Evolution (Maven) spacecraft, a $671 million mission to study the composition of the Martian upper atmosphere, sat at Kennedy Space Center ready to go to space, but with no one there to push the button. Congress and the Obama administration were competing to see who would blink first, but the planets weren’t waiting. If Maven didn’t lift off before the close of its launch window, the position of Mars relative to Earth would force a launch delay of 26 months. This would have had repercussions for Mars missions subsequent to Maven, as well as for scientists awaiting data for study and analysis.

Michoud looks like a place where things are built. Spacecraft, yes, and rockets—the biggest ever imagined—but things all the same. With only slight changes, it could be a place where cars are manufactured, or supercomputers, or valves, or motors. Michoud is like the world's greatest high school metal shop, only instead of turning wrenches to automatic transmissions, the men and women here apply tools to spacecraft. Sheets of metal roll in the front door, and spaceships and rockets roll out the back.

The facility is located on the outskirts of New Orleans, amidst vast footprints of vacant land. Across the street from Michoud is a Folgers Coffee plant, leaving the air outside redolent with the soft bitterness of a newly opened bag of ground coffee. That itself is striking—the mix of coffee, concrete, cars, and cranes. This is where science fiction is realized, and it's all so normal. The workers here are some of the smartest people in the world doing some of the most challenging and important work in the world, but they seem like true workers in the grandest human sense of the word, the kinds of men and women otherwise seen with sleeves rolled up on wartime propaganda posters. Together we can do it! Keep 'em firing!

Mark Kirasich, the program manager of Orion, described the Orion team as the "craftsmen of the 21st century." In some beautiful future of humanity, this is the job where blue collar men and women punch in at 9, ply their trade, punch out, and grab beers before flying home on jetpacks. Today they build Orion spacecraft and the Space Launch System rockets that will take them into space. Previously, they built the 15-story external fuel tanks for the space shuttle, and the first stage of the Saturn V rockets that sent men to the Moon.